In a high pressure gradient pump, each different mobile phase is delivered by an individual pump head and then the mobile phases are mixed at the pump outlet. In a low pressure gradient pump, different mobile phases are mixed using a valve before entering the pump head.
As a result of the fact that the low-pressure gradient design uses only one pump head, it is of lower cost. It can also use more types of mobile phase without significant increase of cost.
Since solvent mixing point is much closer to the column head in the high-pressure gradient design, it provides a much faster gradient. This is measured using delay volume. The value can be 50-300 uL for high pressure gradient pump and can be 2 to 3 times larger for a low pressure gradient pump. A small delay volume is important when the analysis time is short or the flow rate is low. If the delay volume is too large, it become impossible to obtain reproducible gradient run since the planed composition cannot reach the column head before a run is finished.
hi, could any one answer what is the difference between hplc uv detector and spectrophotometer uv detector ? my id is debendra_mallick2002@yahoomail.com
GLC has a stationary liquid phase and gas moving phase HPLC had a stationary solid phase and liquid moving phase HPLC is done under high pressure. HPLC can be used for thermally unstable compounds as opposed to GLC HPLC can be used for polar or low volatile compounds as opposed to GLC
how long time gradient reach column.
flourescence is more sensetive than UV detection
High Pressure Liquid Chromatography
in isocretic system we use only single mobile phase but in gredent system we use two or more mobile phases.
hi, could any one answer what is the difference between hplc uv detector and spectrophotometer uv detector ? my id is debendra_mallick2002@yahoomail.com
specificity and selectivity
GLC has a stationary liquid phase and gas moving phase HPLC had a stationary solid phase and liquid moving phase HPLC is done under high pressure. HPLC can be used for thermally unstable compounds as opposed to GLC HPLC can be used for polar or low volatile compounds as opposed to GLC
how long time gradient reach column.
High Pressure Liquid Chromatography
flourescence is more sensetive than UV detection
The dead volume in HPLC is 137.45. The dead volume in science is used in retention measurements and also in thermodynamic studies and the abbreviation HPLC stands for High Pressure Liquid Chromatography.
What is deference GC, HPLC & GCHS
The dead volume in HPLC is 137.45. The dead volume in science is used in retention measurements and also in thermodynamic studies and the abbreviation HPLC stands for High Pressure Liquid Chromatography.
NP-HPLC is "Normal Phase" HPLC, wherein the solvents used are less polar than the substrate in the HPLC column (e.g. using hexane or dichloromethane with a silica HPLC column). RP-HPLC is "Reverse-Phase" HPLC, wherein the solvents used are more polar than the substrate in the HPLC column (e.g. using Water and Methanol with a octadecylsilane (ODS or C18) column).
HPLC is advanced